1. Field of the Invention
This invention relates to an apparatus in which propylene glycol may be chilled through the utilization of liquid CO.sub.2 to a temperature considerably below freezing to thereby enable food to be immersed in the propylene glycol for quick freezing of the food. Also, the invention further relates to an apparatus which, by the substitution of water for the propylene glycol therein, may be used to produce slush ice and to forcibly project slush ice from the apparatus directly to a point of use such as the interior of a transport container for food stuffs and the like.
2. Description of the Related Art
Various different forms of devices utilizing some of the neral structural and operational features of the instant invention heretofore have been provided such as those disclosed in U.S. Pat. Nos. 1,712,701, 2,893,216, 3,400,551, 4,094,164, 4,680,119, 4,838,039, 4,848,095, 5,092,133 and 5,154,064.
U.S. Pat. No. 5,154,064 includes the same basic construction as that disclosed hereinafter, but provides a circulation pipe which is disposed to the exterior of the tank and which therefore is subject only to ambient air temperature insofar as heat exchange relation is concerned. In addition, in my previously patented device supply water is discharged directly into the tank.
With the instant invention, a second tank is provided into which supply water is discharged to a predetermined level and a communication pipe also is provided for communicating the interiors of the two tanks below the predetermined level of liquid within the second tank. This construction maintains the surface of the water in the second tank reasonably calm for greater control by the float operational water inlet valve. Further, that portion of the circulation pipe of my previously patented slush ice producer which was disposed exteriorly of the tank thereof is enclosed within the second tank of the instant invention below the predetermined liquid level therein and, accordingly, enjoys considerably greater heat exchange relation with the liquid contained within the second tank. This greater heat exchange relation with the liquid within the second tank (which liquid comprises a heat sink) insures that the circulation pipe and the liquid circulating therethrough will not "freeze up" prematurely.